Heat Stoichiometry
• Energy transfer – endothermic vs. exothermic
• Energy diagrams
• Internal energy (including work)
• Heat equation
• Calorimetry and conservation of energy
• Molar enthalpy
• Once you determine the molar
enthalpy of reaction (or you
are given it, you can put it on
the correct side of the
equation.
• And once you’ve done that,
you can treat the heat as a
part of the mole ratio and do
STOICH!!
1) The overall reaction in commercial heat packs can be
represented as:
4 Fe(s) + 3O2(g)  2Fe2O3(s)  H = -1652 kJ
a) How much heat is released when 4.00 mol of iron is reacted
with excess oxygen?
b) How many moles of iron are reacted in excess oxygen to
produce 533 kilojoules of energy?
c) How much heat is released when 1.00 g iron is reacted with
excess oxygen?
d) How much heat is released when 10.0 g of iron reacts with
2.00 g of oxygen?
Grams
STP
gas L
Liters of
solution
Gas
stuff
Grams
Moles
Moles
(or heat)
(or heat)
STP
gas L
Liters of
solution
Gas
stuff